[Elecraft] K3--Too much ALC creates energy on opposite sideband?
I received a note this morning advising that I should check my ALC as he is seeing some energy on USB when I check into a 75m voice net on LSB. I am using an MC-50 microphone and am running the mic gain at 35 and the compression at 11. My thinking was that generating opposite sideband energy would be quite difficult with the K3's DSP. Am I wrong? I'll try working with him some morning and back down the mic gain a bit and see what that does for him. 73, Nate, N0NB -- "The optimist proclaims that we live in the best of all possible worlds. The pessimist fears this is true." Web: https://www.n0nb.us Projects: https://github.com/N0NB GPG fingerprint: 82D6 4F6B 0E67 CD41 F689 BBA6 FB2C 5130 D55A 8819 __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
[Elecraft] K3--Too much ALC creates energy on opposite sideband?
"The more ALC you have, the more the radio is already shutting down down your audio gain and hence the reason it is called Automatic Limiting Control." Can you please cite any modern rig, preferably with reference to the schematics, for which ALC is applied to the audio signal?For the rigs I have studied ALC gain is applied somewhere in the Transmit IF, long after the modulation is applied. Can you please provide any reference that defines ALC as Automatic Limiting Control? 73, Andy, k3wyc __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] K3--Too much ALC creates energy on opposite sideband?
Nate, One thing is that you have a LOT of compression. That may be causing his receiving to show excess energy, maybe even lapping over into the opposite sideband. First set the compression to zero, then either connect a dummy load or use TX TEST and adjust the mic gain for 5 to 7 bars on the ALC meter - the 7 bars should be seen only on peaks. After that, you can increase the compression, but I would limit it to 6 dB for normal operation. 73, Don W3FPR On 8/28/2019 12:40 PM, Nate Bargmann wrote: I received a note this morning advising that I should check my ALC as he is seeing some energy on USB when I check into a 75m voice net on LSB. I am using an MC-50 microphone and am running the mic gain at 35 and the compression at 11. My thinking was that generating opposite sideband energy would be quite difficult with the K3's DSP. Am I wrong? __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] K3--Too much ALC creates energy on opposite sideband?
Nate: You should run your MIC gain such that you see 4 bars of ALC with the 5th just flickering occasionally on voice peaks. Make this adjustment with compression at zero. Then, adjust the compression as desired. I generally set it so that voice peaks show 10 dB compression. The first 4 bars on the ALC display are in fact just a VU meter. ALC action begins at the 5th bar. Elecraft transceivers set the power out with a closed feedback loop [PWR setting], not the MIC gain. Driving the ALC too hard will create IMD which, among other things, will show up as energy on the opposite sideband. It all happens in the RF chain after the DSP has generated the SSB. 73, Fred ["Skip"] K6DGW Sparks NV DM09dn Washoe County On 8/28/2019 9:40 AM, Nate Bargmann wrote: I received a note this morning advising that I should check my ALC as he is seeing some energy on USB when I check into a 75m voice net on LSB. I am using an MC-50 microphone and am running the mic gain at 35 and the compression at 11. My thinking was that generating opposite sideband energy would be quite difficult with the K3's DSP. Am I wrong? I'll try working with him some morning and back down the mic gain a bit and see what that does for him. 73, Nate, N0NB __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] K3--Too much ALC creates energy on opposite sideband?
I have to say it... Maybe he things you have an Icom? :) 73, and thanks, Dave (NK7Z) https://www.nk7z.net ARRL Technical Specialist ARRL Volunteer Examiner ARRL Asst. Director, NW Division, Technical Resources On 8/28/19 9:40 AM, Nate Bargmann wrote: I received a note this morning advising that I should check my ALC as he is seeing some energy on USB when I check into a 75m voice net on LSB. I am using an MC-50 microphone and am running the mic gain at 35 and the compression at 11. My thinking was that generating opposite sideband energy would be quite difficult with the K3's DSP. Am I wrong? I'll try working with him some morning and back down the mic gain a bit and see what that does for him. 73, Nate, N0NB __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] K3--Too much ALC creates energy on opposite sideband?
Although the manual doesn't say so, according to an ARRL review, the K3S is specified to have undesired sideband suppression of >50 dB. ARRL claims an optimistic >70 dB. So if you are extremely strong at the other guy's place, he might easily hear an opposite sideband, even though your radio is operating correctly. Ask him what the ratio is. Wes N7WS On 8/28/2019 9:40 AM, Nate Bargmann wrote: I received a note this morning advising that I should check my ALC as he is seeing some energy on USB when I check into a 75m voice net on LSB. I am using an MC-50 microphone and am running the mic gain at 35 and the compression at 11. My thinking was that generating opposite sideband energy would be quite difficult with the K3's DSP. Am I wrong? I'll try working with him some morning and back down the mic gain a bit and see what that does for him. 73, Nate, N0NB __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] K3--Too much ALC creates energy on opposite sideband?
I don't know about others, but when I got my K3 I did a lot of testing into a dummy load using my previous rig with a short piece of wire for an antenna to monitor my K3 audio. I found anything above about 25 for mic gain was objectionable, at least to me. 73, Dave AB7E On 8/28/2019 9:40 AM, Nate Bargmann wrote: I received a note this morning advising that I should check my ALC as he is seeing some energy on USB when I check into a 75m voice net on LSB. I am using an MC-50 microphone and am running the mic gain at 35 and the compression at 11. My thinking was that generating opposite sideband energy would be quite difficult with the K3's DSP. Am I wrong? I'll try working with him some morning and back down the mic gain a bit and see what that does for him. 73, Nate, N0NB __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] K3--Too much ALC creates energy on opposite sideband?
Hi Fred, The ALC level you recommended is the recommended level for digital modes such as FT8 where no ALC is the standard practice. Elecraft's recommended for the K3 or K3S ALC level when operating in voice modes is 5-7 bars. The exact quote from page 30 of the latest K3S manual https://ftp.elecraft.com/K3S/Manuals%20Downloads/K3S%20Owner's%20man%20A1.pdf Optionally select TX TEST mode (pg. 13) or set power to zero. This will not affect your CMP/ALC bar graph readings. Set CMP to 0 Hold METER to select CMP/ALC metering While speaking into the microphone in a normal voice, adjust MIC for a peak ALC meter indication of about 5-7 bars (see below). Adjust CMP for the desired speech compression level while speaking.The CMP scale shows approximate compression level. 73 Frank W3LPL - Original Message - From: "Fred Jensen" To: elecraft@mailman.qth.net Sent: Wednesday, August 28, 2019 5:19:58 PM Subject: Re: [Elecraft] K3--Too much ALC creates energy on opposite sideband? Nate: You should run your MIC gain such that you see 4 bars of ALC with the 5th just flickering occasionally on voice peaks. Make this adjustment with compression at zero. Then, adjust the compression as desired. I generally set it so that voice peaks show 10 dB compression. The first 4 bars on the ALC display are in fact just a VU meter. ALC action begins at the 5th bar. Elecraft transceivers set the power out with a closed feedback loop [PWR setting], not the MIC gain. Driving the ALC too hard will create IMD which, among other things, will show up as energy on the opposite sideband. It all happens in the RF chain after the DSP has generated the SSB. 73, Fred ["Skip"] K6DGW Sparks NV DM09dn Washoe County On 8/28/2019 9:40 AM, Nate Bargmann wrote: > I received a note this morning advising that I should check my ALC as he > is seeing some energy on USB when I check into a 75m voice net on LSB. > I am using an MC-50 microphone and am running the mic gain at 35 and the > compression at 11. My thinking was that generating opposite sideband > energy would be quite difficult with the K3's DSP. Am I wrong? > > I'll try working with him some morning and back down the mic gain a bit > and see what that does for him. > > 73, Nate, N0NB > __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to donov...@starpower.net __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] K3--Too much ALC creates energy on opposite sideband?
Numerical readouts for Mic Gain and Comp are pretty meaningless, because the output of good mics varies widely from one model to another, how close the mic is to the mouth, how loud we talk. The right way to set (and understand) these controls is to look at indicated ALC and CMP on the bar graph display while transmitting. Both adjustments should be made AFTER setting TXEQ. I have long advocated 10 dB of indicated CMP on voice peaks. It is well known that IMD in the K3 and K3S increases when operating from low DC supply voltage. It also increases when the output stage is operating near its limit, and when the antenna is not well matched to the output stage. If the 100W amp is present, it does not engage until output power is set above about 15W, so IMD is also higher when running 12-15W. The increased IMD of the 100W state can be clearly seen in this set of data. DC voltage was in the range of 12.5V for these measurements. http://k9yc.com/P3_Spectrum_Measurements.pdf Pink noise is widely used by audio professionals because its spectral distribution more closely corresponds to music and speech than does white noise. For that reason, pink noise is the best test signal for the evaluation of speech processing systems (like CMP and peak limiting). 73, Jim K9YC 8/28/2019 10:45 AM, Wes wrote: Although the manual doesn't say so, according to an ARRL review, the K3S is specified to have undesired sideband suppression of >50 dB. ARRL claims an optimistic >70 dB. So if you are extremely strong at the other guy's place, he might easily hear an opposite sideband, even though your radio is operating correctly. Ask him what the ratio is. Wes N7WS On 8/28/2019 9:40 AM, Nate Bargmann wrote: I received a note this morning advising that I should check my ALC as he is seeing some energy on USB when I check into a 75m voice net on LSB. I am using an MC-50 microphone and am running the mic gain at 35 and the compression at 11. My thinking was that generating opposite sideband energy would be quite difficult with the K3's DSP. Am I wrong? I'll try working with him some morning and back down the mic gain a bit and see what that does for him. __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] K3--Too much ALC creates energy on opposite sideband?
Wes, You make a very good point. The unwanted sideband will not be 0; there will be some "residue" that can be heard if the signal is strong enough. And, a lot has to do with the measurement method at the receiver. Years ago, I was running DSBSC using a Globe DSB-100. I was told that my carrier was way down but my unwanted sideband was only 20 db down. That was interesting as I made no effort to suppress my unwanted sideband. The problem was the method that was used to make the measurements and the strength of my signal. So, determining the ratio of the two sidebands might be difficult, but it may be the correct approach, However, it will require being able to "see" both sidebands on an equal basis. 73, Barry K3NDM -- Original Message -- From: "Wes" To: elecraft@mailman.qth.net Sent: 8/28/2019 1:45:11 PM Subject: Re: [Elecraft] K3--Too much ALC creates energy on opposite sideband? Although the manual doesn't say so, according to an ARRL review, the K3S is specified to have undesired sideband suppression of >50 dB. ARRL claims an optimistic >70 dB. So if you are extremely strong at the other guy's place, he might easily hear an opposite sideband, even though your radio is operating correctly. Ask him what the ratio is. Wes N7WS On 8/28/2019 9:40 AM, Nate Bargmann wrote: I received a note this morning advising that I should check my ALC as he is seeing some energy on USB when I check into a 75m voice net on LSB. I am using an MC-50 microphone and am running the mic gain at 35 and the compression at 11. My thinking was that generating opposite sideband energy would be quite difficult with the K3's DSP. Am I wrong? I'll try working with him some morning and back down the mic gain a bit and see what that does for him. 73, Nate, N0NB __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to barrylaz...@gmail.com __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] K3--Too much ALC creates energy on opposite sideband?
What has any of that to do with opposite sideband rejection? Wes N7WS BTW, The HPA kicks in at 12 W. On 8/28/2019 12:55 PM, Jim Brown wrote: Numerical readouts for Mic Gain and Comp are pretty meaningless, because the output of good mics varies widely from one model to another, how close the mic is to the mouth, how loud we talk. The right way to set (and understand) these controls is to look at indicated ALC and CMP on the bar graph display while transmitting. Both adjustments should be made AFTER setting TXEQ. I have long advocated 10 dB of indicated CMP on voice peaks. It is well known that IMD in the K3 and K3S increases when operating from low DC supply voltage. It also increases when the output stage is operating near its limit, and when the antenna is not well matched to the output stage. If the 100W amp is present, it does not engage until output power is set above about 15W, so IMD is also higher when running 12-15W. The increased IMD of the 100W state can be clearly seen in this set of data. DC voltage was in the range of 12.5V for these measurements. http://k9yc.com/P3_Spectrum_Measurements.pdf Pink noise is widely used by audio professionals because its spectral distribution more closely corresponds to music and speech than does white noise. For that reason, pink noise is the best test signal for the evaluation of speech processing systems (like CMP and peak limiting). 73, Jim K9YC 8/28/2019 10:45 AM, Wes wrote: Although the manual doesn't say so, according to an ARRL review, the K3S is specified to have undesired sideband suppression of >50 dB. ARRL claims an optimistic >70 dB. So if you are extremely strong at the other guy's place, he might easily hear an opposite sideband, even though your radio is operating correctly. Ask him what the ratio is. Wes N7WS On 8/28/2019 9:40 AM, Nate Bargmann wrote: I received a note this morning advising that I should check my ALC as he is seeing some energy on USB when I check into a 75m voice net on LSB. I am using an MC-50 microphone and am running the mic gain at 35 and the compression at 11. My thinking was that generating opposite sideband energy would be quite difficult with the K3's DSP. Am I wrong? I'll try working with him some morning and back down the mic gain a bit and see what that does for him. __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] K3--Too much ALC creates energy on opposite sideband?
I agree with Jim and what I tell hams every day since I seem to talk to a bunch of them on the phone. Do NOT use the settings other tell you, set up the radio by using the Meters in the radio, in this case the ALC. That is the reason it is on the radio. The more ALC you have, the more the radio is already shutting down down your audio gain and hence the reason it is called Automatic Limiting Control. I am not a big fan of compression and in today's world there really is no requirement to have it on. Ask anyone who has been DXPedition end of a DXPedition and they will tell you to turn it off as it is actually harder to understand you. It 'might' look like you have more power out, but it is not really in a good way. This is also a good time to review page 28 on "Voice Modes" and follow the steps the way the Engineers who designed this want you to set up your radio. They are pretty smart people. :) I hope that helps, Mike va3mw On Wed, Aug 28, 2019 at 4:33 PM Barry wrote: > Wes, > You make a very good point. The unwanted sideband will not be 0; > there will be some "residue" that can be heard if the signal is strong > enough. And, a lot has to do with the measurement method at the > receiver. > > Years ago, I was running DSBSC using a Globe DSB-100. I was told > that my carrier was way down but my unwanted sideband was only 20 db > down. That was interesting as I made no effort to suppress my unwanted > sideband. The problem was the method that was used to make the > measurements and the strength of my signal. So, determining the ratio of > the two sidebands might be difficult, but it may be the correct > approach, However, it will require being able to "see" both sidebands on > an equal basis. > > 73, > Barry > K3NDM > > -- Original Message ------ > From: "Wes" > To: elecraft@mailman.qth.net > Sent: 8/28/2019 1:45:11 PM > Subject: Re: [Elecraft] K3--Too much ALC creates energy on opposite > sideband? > > >Although the manual doesn't say so, according to an ARRL review, the K3S > is specified to have undesired sideband suppression of >50 dB. ARRL claims > an optimistic >70 dB. > > > >So if you are extremely strong at the other guy's place, he might easily > hear an opposite sideband, even though your radio is operating correctly. > Ask him what the ratio is. > > > >Wes N7WS > > > >On 8/28/2019 9:40 AM, Nate Bargmann wrote: > >>I received a note this morning advising that I should check my ALC as he > >>is seeing some energy on USB when I check into a 75m voice net on LSB. > >>I am using an MC-50 microphone and am running the mic gain at 35 and the > >>compression at 11. My thinking was that generating opposite sideband > >>energy would be quite difficult with the K3's DSP. Am I wrong? > >> > >>I'll try working with him some morning and back down the mic gain a bit > >>and see what that does for him. > >> > >>73, Nate, N0NB > >> > > > >__ > >Elecraft mailing list > >Home: http://mailman.qth.net/mailman/listinfo/elecraft > >Help: http://mailman.qth.net/mmfaq.htm > >Post: mailto:Elecraft@mailman.qth.net > > > >This list hosted by: http://www.qsl.net > >Please help support this email list: http://www.qsl.net/donate.html > >Message delivered to barrylaz...@gmail.com > > __ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:Elecraft@mailman.qth.net > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to va...@portcredit.net > __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] K3--Too much ALC creates energy on opposite sideband?
Barry, With my SDR-IQ looking at the K3S i-f output I can see the other guy's signature. I suppose a P3 does the same. It's pretty amazing to see some of the lousy signals when we have such improved technology. Wes On 8/28/2019 1:30 PM, Barry wrote: Wes, You make a very good point. The unwanted sideband will not be 0; there will be some "residue" that can be heard if the signal is strong enough. And, a lot has to do with the measurement method at the receiver. Years ago, I was running DSBSC using a Globe DSB-100. I was told that my carrier was way down but my unwanted sideband was only 20 db down. That was interesting as I made no effort to suppress my unwanted sideband. The problem was the method that was used to make the measurements and the strength of my signal. So, determining the ratio of the two sidebands might be difficult, but it may be the correct approach, However, it will require being able to "see" both sidebands on an equal basis. 73, Barry K3NDM -- Original Message -- From: "Wes" To: elecraft@mailman.qth.net Sent: 8/28/2019 1:45:11 PM Subject: Re: [Elecraft] K3--Too much ALC creates energy on opposite sideband? Although the manual doesn't say so, according to an ARRL review, the K3S is specified to have undesired sideband suppression of >50 dB. ARRL claims an optimistic >70 dB. So if you are extremely strong at the other guy's place, he might easily hear an opposite sideband, even though your radio is operating correctly. Ask him what the ratio is. Wes N7WS On 8/28/2019 9:40 AM, Nate Bargmann wrote: I received a note this morning advising that I should check my ALC as he is seeing some energy on USB when I check into a 75m voice net on LSB. I am using an MC-50 microphone and am running the mic gain at 35 and the compression at 11. My thinking was that generating opposite sideband energy would be quite difficult with the K3's DSP. Am I wrong? I'll try working with him some morning and back down the mic gain a bit and see what that does for him. 73, Nate, N0NB __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to barrylaz...@gmail.com __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] K3--Too much ALC creates energy on opposite sideband?
On 8/28/2019 1:46 PM, Michael Walker wrote: I am not a big fan of compression and in today's world there really is no requirement to have it on. Ask anyone who has been DXPedition end of a DXPedition and they will tell you to turn it off as it is actually harder to understand you. This is NOT true if compression is well adjusted -- 10 dB of well adjusted compression increases talk power by 10 dB, and setting TXEQ to remove speech content below 400 Hz helps by another 3 dB. It is the abuse of compression that reduces intelligibility. Compression has been universally used in all broadcasting modes for at least 60 years, and for at least 40 years, for gain reductions of 30 dB or more! The joke among FM broadcast engineers in the '70s was "If the meter in the modulation monitor moves, the program director will say we're not loud enough!" 73, Jim K9YC __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] K3--Too much ALC creates energy on opposite sideband?
Yes, I know what the manual says. However the IMD on my K3 goes up when I set the mic gain to flicker bar 7 on voice peaks so I run it with almost no ALC. I also set the TX EQ using the "K9YC Method," and regularly get unsolicited "great audio" comments so I'm a fairly happy ham. I'm not on SSB often, but when I do get on such as NAQP SSB, I'm always a bit surprised at how many signals have all the sideband energy crammed right up against the suppressed carrier. Not too many fill up their BW. For those of us with compromised hearing, it makes copy difficult ... one of the several reasons I don't get on phone very often. All that low frequency energy contributes almost nothing to intelligibility. 73, Fred ["Skip"] K6DGW Sparks NV DM09dn Washoe County On 8/28/2019 11:05 AM, donov...@starpower.net wrote: Hi Fred, The ALC level you recommended is the recommended level for digital modes such as FT8 where *no ALC* is the standard practice. Elecraft's recommended for the K3 or K3S ALC level when operating in voice modes is *5-7 bars.* The exact quote from page 30 of the latest K3S manual https://ftp.elecraft.com/K3S/Manuals%20Downloads/K3S%20Owner's%20man%20A1.pdf Optionally select TX TEST mode (pg. 13) or set power to zero. This will not affect your CMP/ALC bar graph readings. Set CMP to 0 Hold METER to select CMP/ALC metering While speaking into the microphone in a normal voice, adjust MIC for a peak ALC meter indication of about *5-7 bars* (see below). Adjust CMP for the desired speech compression level while speaking.The CMP scale shows approximate compression level. 73 Frank W3LPL __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] K3--Too much ALC creates energy on opposite sideband?
On 8/28/2019 1:50 PM, Wes wrote: With my SDR-IQ looking at the K3S i-f output I can see the other guy's signature. I suppose a P3 does the same. It's pretty amazing to see some of the lousy signals when we have such improved technology. Yes. I regularly see signals from SSB ragchewers with splatter in the suppressed sideband only 10-15 dB below signal in the intentional sideband. The data in the link I posted was with a P3 on my second K3, with the K3 being measured into a dummy load. I've alerted guys on 6M about this, suggesting they turn down drive to their amplifier, and they said they didn't have an amplifier. When I asked what rig, it was one of the low-cost do-everything rigs from one of the big JA mfrs. When I posted this at the time, W4TV described the mechanism (I think I remember that it was a shortcominBefore Elecraft rigs took over Field Day, These cheap rigs (and even some much more expensive ones) have long been considered the scourge of Field Day. 73, Jim K9YC __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] K3--Too much ALC creates energy on opposite sideband?
It seems like often Jim and I disagree on things, but this time I'm in total agreement with him. About a year after my speech processor paper was published in Ham Radio Magazine (http://k6mhe.com/n7ws/S_PROC.pdf) I worked a guy in the PNW, on ten meters. He was running a homebrew 2 watt radio and using a copy of my processor. He was delighted with it and the fact that we were talking. Frankly, it was the first time I'd heard one from the other end. So he wanted to experiment. He was about S2 but perfectly Q5. When he turned the processor off he was gone. Not a peep. It was amazing. Frankly, I was impressed. I knew the theory but to see it in action was eyeopening. Wes N7WS On 8/28/2019 2:18 PM, Jim Brown wrote: On 8/28/2019 1:46 PM, Michael Walker wrote: I am not a big fan of compression and in today's world there really is no requirement to have it on. Ask anyone who has been DXPedition end of a DXPedition and they will tell you to turn it off as it is actually harder to understand you. This is NOT true if compression is well adjusted -- 10 dB of well adjusted compression increases talk power by 10 dB, and setting TXEQ to remove speech content below 400 Hz helps by another 3 dB. It is the abuse of compression that reduces intelligibility. Compression has been universally used in all broadcasting modes for at least 60 years, and for at least 40 years, for gain reductions of 30 dB or more! The joke among FM broadcast engineers in the '70s was "If the meter in the modulation monitor moves, the program director will say we're not loud enough!" 73, Jim K9YC __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] K3--Too much ALC creates energy on opposite sideband?
I think I better take a mea culpa on this one. One reply in a private email asked if I was using and amp and whether I was driving it too hard. Well, some mornings this week I have depending on static levels and I operated the KS QSO Party this past weekend and ran 100W. I normally run the amp (ALS-600) with the power setting at 70W. This is probably just a, "D'oh!" moment. Yes, the K3 was still set for 100W. Incidentally, My COMP runs about 2-3 bars on voice peaks and the ALC meter is in the 5-7 bars range on peaks as well. It's a PEBCAK3 issue. ;-) -- "The optimist proclaims that we live in the best of all possible worlds. The pessimist fears this is true." Web: https://www.n0nb.us Projects: https://github.com/N0NB GPG fingerprint: 82D6 4F6B 0E67 CD41 F689 BBA6 FB2C 5130 D55A 8819 __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] K3--Too much ALC creates energy on opposite sideband?
Hi Fred (Skip) Sadly, many of those are splattering so wide that you can hear them on the opposite sideband. Unfortunately, a report of great audio does not mean great IMD performance. Don't take this the wrong way, I am not saying you have bad IMD it just that you can't relate the 2 has being an indicator. With a good radio and a good waterfall you can see it plain as day. There are a few locals (aka here in ve3 land) that I 'watch' routinely with their top end Yaesu's (5000's) and they sound awesome, but they have the absolute worst splatter you have ever seen.One guy on 80M was absolutely understandable when I listened to him on USB. Nate, glad you got it figured out. I'm sure we have all been there (me included). 73 all, Mike va3mw On Wed, Aug 28, 2019 at 9:43 PM Nate Bargmann wrote: > I think I better take a mea culpa on this one. One reply in a private > email asked if I was using and amp and whether I was driving it too > hard. Well, some mornings this week I have depending on static levels > and I operated the KS QSO Party this past weekend and ran 100W. I > normally run the amp (ALS-600) with the power setting at 70W. > > This is probably just a, "D'oh!" moment. Yes, the K3 was still set for > 100W. > > Incidentally, My COMP runs about 2-3 bars on voice peaks and the ALC > meter is in the 5-7 bars range on peaks as well. > > It's a PEBCAK3 issue. ;-) > > -- > > "The optimist proclaims that we live in the best of all > possible worlds. The pessimist fears this is true." > > Web: https://www.n0nb.us > Projects: https://github.com/N0NB > GPG fingerprint: 82D6 4F6B 0E67 CD41 F689 BBA6 FB2C 5130 D55A 8819 > > __ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:Elecraft@mailman.qth.net > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to va...@portcredit.net > __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] K3--Too much ALC creates energy on opposite sideband?
We've made great technical strides in receivers. Transmitters, well they are best described still as "out house" technology. Nothing has changed of significance in 25+ years. In looking at my P3 and SSB signals on the bands, there are lots and lots of really bad signals. Yet I most often hear "great signal" given as a report. 73 Bob, K4TAX On 8/28/2019 3:50 PM, Wes wrote: Barry, With my SDR-IQ looking at the K3S i-f output I can see the other guy's signature. I suppose a P3 does the same. It's pretty amazing to see some of the lousy signals when we have such improved technology. Wes On 8/28/2019 1:30 PM, Barry wrote: Wes, You make a very good point. The unwanted sideband will not be 0; there will be some "residue" that can be heard if the signal is strong enough. And, a lot has to do with the measurement method at the receiver. Years ago, I was running DSBSC using a Globe DSB-100. I was told that my carrier was way down but my unwanted sideband was only 20 db down. That was interesting as I made no effort to suppress my unwanted sideband. The problem was the method that was used to make the measurements and the strength of my signal. So, determining the ratio of the two sidebands might be difficult, but it may be the correct approach, However, it will require being able to "see" both sidebands on an equal basis. 73, Barry K3NDM -- Original Message -- From: "Wes" To: elecraft@mailman.qth.net Sent: 8/28/2019 1:45:11 PM Subject: Re: [Elecraft] K3--Too much ALC creates energy on opposite sideband? Although the manual doesn't say so, according to an ARRL review, the K3S is specified to have undesired sideband suppression of >50 dB. ARRL claims an optimistic >70 dB. So if you are extremely strong at the other guy's place, he might easily hear an opposite sideband, even though your radio is operating correctly. Ask him what the ratio is. Wes N7WS On 8/28/2019 9:40 AM, Nate Bargmann wrote: I received a note this morning advising that I should check my ALC as he is seeing some energy on USB when I check into a 75m voice net on LSB. I am using an MC-50 microphone and am running the mic gain at 35 and the compression at 11. My thinking was that generating opposite sideband energy would be quite difficult with the K3's DSP. Am I wrong? I'll try working with him some morning and back down the mic gain a bit and see what that does for him. 73, Nate, N0NB __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to barrylaz...@gmail.com __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to rmcg...@blomand.net __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] K3--Too much ALC creates energy on opposite sideband?
I find a lot of the opposite sideband splatter is originated from mis-tuned amplifiers or amplifiers which are driven too hard. If it isn't "linear" it is a splatter generator. And linear means just that, linear. For an amp to be linear, it must amplify all signal levels the same amount. Most amplifiers begin to show some degree of signal compression at the upper power rating limits. Pushing one past these limits even the slightest amount, generate significant amounts of opposite sideband splatter. 73 Bob, K4TAX On 8/28/2019 4:27 PM, Jim Brown wrote: On 8/28/2019 1:50 PM, Wes wrote: Yes. I regularly see signals from SSB ragchewers with splatter in the suppressed sideband only 10-15 dB below signal in the intentional sideband. The data in the link I posted was with a P3 on my second K3, with the K3 being measured into a dummy load. I've alerted guys on 6M about this, suggesting they turn down drive to their amplifier, and they said they didn't have an amplifier. When I asked what rig, it was one of the low-cost do-everything rigs from one of the big JA mfrs. When I posted this at the time, W4TV described the mechanism (I think I remember that it was a shortcominBefore Elecraft rigs took over Field Day, These cheap rigs (and even some much more expensive ones) have long been considered the scourge of Field Day. 73, Jim K9YC __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to rmcg...@blomand.net __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] K3--Too much ALC creates energy on opposite sideband?
So very true. I'm about as far removed from being an AM/audiophile type of ham as you could imagine, but I've heard guys getting "great audio" reports when they sounded like trash with lots of clipping. It's really sad, and I tend to err on the conservative side because I'd rather give up a bit of "punch" than be one of them. 73, Dave AB7E On 8/28/2019 7:46 PM, Bob McGraw K4TAX wrote: In looking at my P3 and SSB signals on the bands, there are lots and lots of really bad signals. Yet I most often hear "great signal" given as a report. 73 Bob, K4TAX __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] K3--Too much ALC creates energy on opposite sideband?
I have measured the TX IMD performance of my and 2 other K3S transceivers. In my opinion it is not possible to have anything other than mediocre TX IMD performance from a K3S or a K3 at ANY power level. I am so disappointed with this aspect of the K3S. The mass market and cheap IC-7300 is better, especially on 6m. In all other respects I am very impressed with the K3S. The transverter output on 10m when set to 0.5mW has incredibly good IMD performance so the problem is with the 2 PA modules. I have contacted Elecraft and so far they have not offered me a satisfactory solution. I think that I am going to go to the inconvenience of using an external PA on 6m. The K3S has excellent TX composite noise all ruined by poor TX IMD. I can easily see 19th and 21st order IMD components on 6m in the 90dB dynamic range of my E4406A spectrum analyser - this rather negates the advantage to my neighbours when I'm on SSB. For CW and Digimodes then the K3S is superb. If I was contemplating the purchase of a K4 I would be asking Elecraft about TX IMD from the hopefully new and improved TX amplifier chain. Not a happy message but it's the truth. Yes I have the latest FW, yes I have tried to reduce the gain from the driver using the settings in the FW yes I maintain the correct voltage on the PA, yes I have late (not the latest) revisions of the driver and final PA. I am using the 2 tone facility so there is no question of external or maladjusted audio non linearity. The fact is that it is poor. I also know what I'm doing. Poor show Elecraft! 73 Conrad PA5Y From: elecraft-boun...@mailman.qth.net on behalf of Michael Walker Sent: 29 August 2019 04:02 To: Elecraft@mailman.qth.net Subject: Re: [Elecraft] K3--Too much ALC creates energy on opposite sideband? Hi Fred (Skip) Sadly, many of those are splattering so wide that you can hear them on the opposite sideband. Unfortunately, a report of great audio does not mean great IMD performance. Don't take this the wrong way, I am not saying you have bad IMD it just that you can't relate the 2 has being an indicator. With a good radio and a good waterfall you can see it plain as day. There are a few locals (aka here in ve3 land) that I 'watch' routinely with their top end Yaesu's (5000's) and they sound awesome, but they have the absolute worst splatter you have ever seen.One guy on 80M was absolutely understandable when I listened to him on USB. Nate, glad you got it figured out. I'm sure we have all been there (me included). 73 all, Mike va3mw On Wed, Aug 28, 2019 at 9:43 PM Nate Bargmann wrote: > I think I better take a mea culpa on this one. One reply in a private > email asked if I was using and amp and whether I was driving it too > hard. Well, some mornings this week I have depending on static levels > and I operated the KS QSO Party this past weekend and ran 100W. I > normally run the amp (ALS-600) with the power setting at 70W. > > This is probably just a, "D'oh!" moment. Yes, the K3 was still set for > 100W. > > Incidentally, My COMP runs about 2-3 bars on voice peaks and the ALC > meter is in the 5-7 bars range on peaks as well. > > It's a PEBCAK3 issue. ;-) > > -- > > "The optimist proclaims that we live in the best of all > possible worlds. The pessimist fears this is true." > > Web: https://www.n0nb.us > Projects: https://github.com/N0NB > GPG fingerprint: 82D6 4F6B 0E67 CD41 F689 BBA6 FB2C 5130 D55A 8819 > > __ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:Elecraft@mailman.qth.net > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to va...@portcredit.net > __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to g0...@g0ruz.com __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] K3--Too much ALC creates energy on opposite sideband?
This thread instigated some experiments here. In analyzing TX IMD in both my K3 and K3S, I've made probably hundreds of two-tone measurements using the built-in two-tone generator. But in all of these measurements I never questioned what the audio level was, since it's not adjustable, except for balancing the levels of the tones. So I set up a measurement and went to transmit and then using the K3 utility used the get "BG" command to read the ALC bar graph. The answer was zero bars. I found this interesting. To explore further, as a proxy audio signal generator, I opened WSJT-X, FT-8 mode and used the "Test" button to generate an audio tone. I used both the K3S internal sound card and the built-in card in a Lenovo Think Pad as a double check against generator distortion. I saw similar results with both. And what are those results you ask. Using a spectrum analyzer and looking at the K3S output on 14 MHz in this case, using a low tone (500+ Hz) I noted that at any audio level that drove the ALC indicator to four bars (even flickering), there was low level garbage that appeared in the TX passband. It took reducing the level to three bars to clean it up and in my radio there are either three bars or none, no one or two, when reducing the gain. The "BG" command confirmed this. Above four bars, things only got worse. Understand this was low-level stuff down in the weeds and not the dreaded audio harmonics that WSJT-X "split" is supposed to prevent. I've never been one of those handwringers worrying about using ALC, as I believe just like AGC in receivers that we all use, properly designed it should work well for its intended purpose. Now, I'm not so sure, perhaps I've been wrong or I'm saved by the "properly designed" clause. Wes N7WS On 8/28/2019 2:22 PM, Fred Jensen wrote: Yes, I know what the manual says. However the IMD on my K3 goes up when I set the mic gain to flicker bar 7 on voice peaks so I run it with almost no ALC. I also set the TX EQ using the "K9YC Method," and regularly get unsolicited "great audio" comments so I'm a fairly happy ham. I'm not on SSB often, but when I do get on such as NAQP SSB, I'm always a bit surprised at how many signals have all the sideband energy crammed right up against the suppressed carrier. Not too many fill up their BW. For those of us with compromised hearing, it makes copy difficult ... one of the several reasons I don't get on phone very often. All that low frequency energy contributes almost nothing to intelligibility. 73, Fred ["Skip"] K6DGW Sparks NV DM09dn Washoe County __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] K3--Too much ALC creates energy on opposite sideband?
Conrad and I have corresponded about this in the past. He is absolutely correct in worrying about the IMD performance of the K4. I bought my K3S after being disappointed with the K3 TX IMD and thinking that the FETs would be better. How wrong I was. IMD was no improvement and reliability was awful. At 50 VDC, they no doubt would be better but as long as Elecraft clings to "12-volt" radios, I'm afraid this will persist. Wes N7WS On 8/29/2019 5:04 AM, Conrad PA5Y wrote: I have measured the TX IMD performance of my and 2 other K3S transceivers. In my opinion it is not possible to have anything other than mediocre TX IMD performance from a K3S or a K3 at ANY power level. I am so disappointed with this aspect of the K3S. The mass market and cheap IC-7300 is better, especially on 6m. In all other respects I am very impressed with the K3S. The transverter output on 10m when set to 0.5mW has incredibly good IMD performance so the problem is with the 2 PA modules. I have contacted Elecraft and so far they have not offered me a satisfactory solution. I think that I am going to go to the inconvenience of using an external PA on 6m. The K3S has excellent TX composite noise all ruined by poor TX IMD. I can easily see 19th and 21st order IMD components on 6m in the 90dB dynamic range of my E4406A spectrum analyser - this rather negates the advantage to my neighbours when I'm on SSB. For CW and Digimodes then the K3S is superb. If I was contemplating the purchase of a K4 I would be asking Elecraft about TX IMD from the hopefully new and improved TX amplifier chain. Not a happy message but it's the truth. Yes I have the latest FW, yes I have tried to reduce the gain from the driver using the settings in the FW yes I maintain the correct voltage on the PA, yes I have late (not the latest) revisions of the driver and final PA. I am using the 2 tone facility so there is no question of external or maladjusted audio non linearity. The fact is that it is poor. I also know what I'm doing. Poor show Elecraft! 73 Conrad PA5Y __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] K3--Too much ALC creates energy on opposite sideband?
There is a big difference between "energy on opposite sideband" and hearing the opposite sideband. If you switch to the opposite sideband and can clearly copy the intelligence, then the issue is sideband suppression. If you hear unintelligible audio from the offending signal, that is splatter with many possible causes, one of which is IMD in the exciter, amplifier, or both. ALC is frequently abused with the offending op receiving great audio reports. I find many who never monitor ALC while operating SSB. Few ops give accurate audio quality reports today, much less pay attention to TX bandwidth when providing reports in spite of the proliferation of SDR's and panadapters. Most don't know the difference between RFI in the TX audio chain and an over-driven signal. We need to mentor our brethren to help guide them in the right direction. While some might consider this nitpicking, ours is a service based on science and facts. However, science and facts are too often ignored. I use screen captures from my P3 when pointing out broad signals. Half of the offending ops don't have an e-mail on QRZ.com. Half of those who do are surprised to learn of their transmitter bandwidth "abuse." A significant portion of those don't care and are offended. Fortunately, that is rarely the case here. 73, Bill, K8TE "Sadly, many of those are splattering so wide that you can hear them on the opposite sideband. Unfortunately, a report of great audio does not mean great IMD performance." -- Sent from: http://elecraft.365791.n2.nabble.com/ __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] K3--Too much ALC creates energy on opposite sideband?
Has anyone collected IMD data on the different version of KPA3A amps? I seem to recall measuring IMD when I first got my K3S, s/n 10163. Since that time I' have experienced 2 failures of the KPA3A in my radio. Elecraft replaced the last one with a newer "more stable" version. I do run my radio with 14.2 volts at the radio in transmit at 100 watts output CW key closed. In RX the voltage is 14.5. The 0.3 volt difference is the IR drop in the DC power cable and connector. Guess I need to measure that one. But hey, it too pretty and very comfortable outside. I'll save that for another lousy weather day. 73 Bob, K4TAX On 8/29/2019 12:09 PM, Wes wrote: Conrad and I have corresponded about this in the past. He is absolutely correct in worrying about the IMD performance of the K4. I bought my K3S after being disappointed with the K3 TX IMD and thinking that the FETs would be better. How wrong I was. IMD was no improvement and reliability was awful. At 50 VDC, they no doubt would be better but as long as Elecraft clings to "12-volt" radios, I'm afraid this will persist. Wes N7WS On 8/29/2019 5:04 AM, Conrad PA5Y wrote: I have measured the TX IMD performance of my and 2 other K3S transceivers. In my opinion it is not possible to have anything other than mediocre TX IMD performance from a K3S or a K3 at ANY power level. I am so disappointed with this aspect of the K3S. The mass market and cheap IC-7300 is better, especially on 6m. In all other respects I am very impressed with the K3S. The transverter output on 10m when set to 0.5mW has incredibly good IMD performance so the problem is with the 2 PA modules. I have contacted Elecraft and so far they have not offered me a satisfactory solution. I think that I am going to go to the inconvenience of using an external PA on 6m. The K3S has excellent TX composite noise all ruined by poor TX IMD. I can easily see 19th and 21st order IMD components on 6m in the 90dB dynamic range of my E4406A spectrum analyser - this rather negates the advantage to my neighbours when I'm on SSB. For CW and Digimodes then the K3S is superb. If I was contemplating the purchase of a K4 I would be asking Elecraft about TX IMD from the hopefully new and improved TX amplifier chain. Not a happy message but it's the truth. Yes I have the latest FW, yes I have tried to reduce the gain from the driver using the settings in the FW yes I maintain the correct voltage on the PA, yes I have late (not the latest) revisions of the driver and final PA. I am using the 2 tone facility so there is no question of external or maladjusted audio non linearity. The fact is that it is poor. I also know what I'm doing. Poor show Elecraft! 73 Conrad PA5Y __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to rmcg...@blomand.net __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] K3--Too much ALC creates energy on opposite sideband?
I assume the measurements with bare K3/K3S were using 100w internal
amp. I wonder how the 10w version of these radios Tx IMD perform?
On 6m, I run with the KXPA100 at 11w output (K3 at very low output)
to drive a 1000w Harris surplus TV linear (which is rated to 1600w
continuous duty). 1000w limit is due to the 50v-50A PS input
limit. On 2m+ I use the 1mw transverter interface output at 28-MHz
on my K3. My 2m 1500w and 23cm 600w LDMOS operate on 50v and I load
to 1-dB output compression point: 2m at 1200w, 23cm at 560w.
Any IMD analysis on the KXPA100?
73, Ed - KL7UW
From: Conrad PA5Y
To: Michael Walker , "Elecraft@mailman.qth.net"
Subject: Re: [Elecraft] K3--Too much ALC creates energy on opposite
sideband?
I have measured the TX IMD performance of my and 2 other K3S
transceivers. In my opinion it is not possible to have anything other
than mediocre TX IMD performance from a K3S or a K3 at ANY power
level. I am so disappointed with this aspect of the K3S. The mass
market and cheap IC-7300 is better, especially on 6m. In all other
respects I am very impressed with the K3S.
73, Ed - KL7UW
http://www.kl7uw.com
Dubus-NA Business mail:
dubus...@gmail.com
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Re: [Elecraft] K3--Too much ALC creates energy on opposite sideband?
Wes Kenwood have delivered a very credible IMD performance from the new TS-890S and, indeed, even the TS-590s (especially the SG) are considerably better than the Elecraft offerings. All are 12 V radios, of course. I use a TS-890S with a KPA1500 and, while the combination is poorer in IMD terms than my 50-yo Collins S-line, it's a great deal better than many contemporary offerings. I don't anticipate parting with the TS-890S any time soon but, all things being equal, regard a K4 with good pre-distortion implementation as a deal maker in the not too distant future. Indeed, I might have waited for a K4 this time around, barring the shenanigans surrounding the K4 forum discussion and announcement. Peter, VK6HP. -Original Message- From: elecraft-boun...@mailman.qth.net On Behalf Of Wes Sent: Friday, 30 August 2019 1:10 AM To: elecraft@mailman.qth.net Subject: Re: [Elecraft] K3--Too much ALC creates energy on opposite sideband? Conrad and I have corresponded about this in the past. He is absolutely correct in worrying about the IMD performance of the K4. I bought my K3S after being disappointed with the K3 TX IMD and thinking that the FETs would be better. How wrong I was. IMD was no improvement and reliability was awful. At 50 VDC, they no doubt would be better but as long as Elecraft clings to "12-volt" radios, I'm afraid this will persist. Wes N7WS On 8/29/2019 5:04 AM, Conrad PA5Y wrote: > I have measured the TX IMD performance of my and 2 other K3S transceivers. In > my opinion it is not possible to have anything other than mediocre TX IMD > performance from a K3S or a K3 at ANY power level. I am so disappointed with > this aspect of the K3S. The mass market and cheap IC-7300 is better, > especially on 6m. In all other respects I am very impressed with the K3S. > > > The transverter output on 10m when set to 0.5mW has incredibly good IMD > performance so the problem is with the 2 PA modules. I have contacted > Elecraft and so far they have not offered me a satisfactory solution. I think > that I am going to go to the inconvenience of using an external PA on 6m. > > > The K3S has excellent TX composite noise all ruined by poor TX IMD. I can > easily see 19th and 21st order IMD components on 6m in the 90dB dynamic range > of my E4406A spectrum analyser - this rather negates the advantage to my > neighbours when I'm on SSB. For CW and Digimodes then the K3S is superb. If I > was contemplating the purchase of a K4 I would be asking Elecraft about TX > IMD from the hopefully new and improved TX amplifier chain. > > > Not a happy message but it's the truth. Yes I have the latest FW, yes I have > tried to reduce the gain from the driver using the settings in the FW yes I > maintain the correct voltage on the PA, yes I have late (not the latest) > revisions of the driver and final PA. I am using the 2 tone facility so there > is no question of external or maladjusted audio non linearity. The fact is > that it is poor. I also know what I'm doing. > > > Poor show Elecraft! > > > 73 > > > Conrad PA5Y > __ Elecraft mailing list Home: http://secure-web.cisco.com/1RrdgZXSnhmLAY_lbN4qKiWPuu_d2_Rin4oYknooNe9PoZH6r2XpnYKMxQFa0OuEy522SMlmuiZC_aIU-nwBLAJEn1QIUUWJ3rZuVONLvqLg5pu-VTOYl7EJtMst-SRfASbXOOdisf9JXYSscQjIOhaxZutHpCYe9bZPD7EujJ0QVEOLmJWfwksv6NXV-LTVJvKKEo2smKZXuZoeZW51AKEY5RU6dtPOb8xuGhmXpOI2V8DSD23MZTkWhwSUW9xaC2AVLZnCU8Az3n5Xt_Je4ub_N7kKtDCPQ20ZGd6Cxn65g012dejR1eZOwSipcWq9cbf31q06hgDt07nsGw6mXPlsR8yb28ku8Q6dPWim-bpCNp_KVXVi-CdyACLh36jnpeit36YqAULGO4codVPIZReBGa7Wssx9_2ldAqb1cRcztxD4SH0OewY4iLH61V5IAVPC4z42iHc2d9pztOxawHpY8KwbM17Z-TtetiL_T668/http%3A%2F%2Fmailman.qth.net%2Fmailman%2Flistinfo%2Felecraft Help: http://secure-web.cisco.com/1MNZxUEzTafvOANOXLoK_vJvodRC_LlCHQRTdRYGD7-6_4L92eD5UD-39n_HaXZZ1CApPLaKoApfn4GyixDVAsaNWGSrOr6T9t3iw0hworoMK2GxIPxBgfYR-ZZ6y3kYC5OCaXxxuDBIF2l6cZ41MxywuTfHOSAkwgl34jmlTbHi2j9jfPa_BdpzAYP3S2jI_xurncS4jTqpA3-G9p-cCZf9iwXx_wxcHSZD_3WXXVCkha8nwiFzX8cWorb92mnAV_p-PByPDWTNr9EjWhGl_J6gO3xGPUwMF-jnQvcTy5ExZ71v5alvt4ZeCFxHndULznDvk5y92Y3swuKfJGiREwGsVESRJg7YVY5-TwvLfTVwojZ3HUczDgBrv4733zgIIN1SixuHe1gYPaX-TrPcKf9O_Po28q4RdgI6U6Xp8Ezrd9SFLONsDDKq7j9pt1mGZuZNFaFyJPm-FmLOnh-0I-NRZgif44BaIY1nMKPZvUCY/http%3A%2F%2Fmailman.qth.net%2Fmmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to p.h...@curtin.edu.au __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
